Well you may think to yourself saiyan hair what makes there hair any different than a humans well let me tell you ALOT is different between a saiyans hair and a humans hair. First off a saiyans hair never changes(does not grow) the hair they are born with stays that way unless they cut it off, and they can be born with extremely long hair such as in Radditz's case. Also when they go super saiyan there hair stands on end and it forms spikes and there hair color turns from the normal color to blonde. In super saiyan level 2 there hair remains blonde and stands more on end with more spikes that are well defined. When a saiyan is in super saiyan level 3 there hair is blonde and grows in length down there back and still has a lot of well defined spikes. This is the part where it gets odd, in super saiyan level 4 there hair turns its normal color and grows longer some not anywhere near as long as in super saiyan level 4 but you can still notice a change. There is an explanation of saiyan hair and how it is different than human hair.